Dust boot for tread brake units

ABSTRACT

A split- or seam-type cone-shaped replaceable dust boot for surrounding the brake rod of a tread brake assembly wherein the boot is disposed in surrounding relation to the brake rod so as to be readily removable and replaceable without disassembly or removal of the associated brake assembly parts. This seam-type dust boot is installed in surrounding relation to the brake rod while the edges of the split seam are separated, following which these edges are secured together in a sealed relationship by overlapping and interlocking ribs on the mating edges. If desired, a slide-fastener element may be employed to effectuate the interlocking of the ribs on the mating edges.

I United States Patent [151 3,638,503

Stipanovic et a1. Feb. 1, 1972 [54] DUST BOOT FOR TREAD BRAKE UNITS3,259,951 7/1966 Zimmerman ..24/201 C [72] Inventors: Joseph G.Stipanovic, McKeesport; E R 3,338,355 8/1967 Kyllonen ..188/202 Allan,Monroeville, both of Pa. Primary Examiner wimam ODea [73] Assignee:Westinghouse Air Brake Company, Wil- Assisllm! r h maker di pAlt0rneyRalph W. Mclntire, Jr.

[22] Filed: Oct. 3, 1969 57 ABSTRACT [2]] Appl- N05 863550 A splitorseam-type cone-shaped replaceable dust boot for surrounding the brakerod of a tread brake assembly wherein 52] us. C1. ..74/18, 24/201 074118.2 the is disPosed summing relation the brake 188/202 as to bereadily removable and replaceable without disas- 51 Int. Cl ..Fl6j 15/50semb'y aswciamd brake assembly Pam [58] Field of Search 74/182 l 188/1985 203 This seam-type dust boot is installed in surrounding relation to'24l201 64/32 the brake rod while the edges of the split seam areseparated, following which these edges are secured together in a sealedrelationship by overlapping and interlocking ribs on the mat- [56]Reerences Cited ing edges. If desired, a slide-fastener element may beem- UNITED STAT A ENTS ployed to effectuate the interlocking of the ribson the mating ed es. 2,210,847 8/1940 Berman ..64/32 F g 2,867,8771/1959 Staller et a1. ..24/201 C 4 Claims, 6 Drawing Figures PATENIEDFEB I 8721 SHEEI 1 0F 2 INVENTOR. JOSEPH G. STIPANOVIC EARL E. ALLAN BYJ fiW/ W ATTORNEY mamas H972. 3538.503

' sum 2 or 2 INVENTOR. JOSEPH G. STIPANOVIC E ARL E. AL I. AN

KWWWMQZ ATTORNEY DUST BOOT FOR TREAD BRAKE UNITS BACKGROUND OF INVENTIONTread brake assemblies presently in use on American railroads areprovided with a cone-shaped seamless boot that is disposed in coaxialsurrounding relation to the brake rod of the assembly with its smallerend sealing on the brake rod whereas its larger end has an out-turnedflange which is secured in abutting sealing relationship to the exteriorof the brake assembly. The boot thus serves to prevent the accumulationof ice and snow on the periphery of the brake rod during cold weatherand also the entrance of dirt, and moisture to the interior of thecasing. To replace a worn or defective scam interior less-type dustboot, it is often necessary to disconnect the brake rod and brake headfrom the brake hanger by removing the pin or bolt that secures theseparts together which of course is both troublesome and time consuming.In some tread brake assembly installations where clearance is at aminimum, the complete tread brake assembly must be removed from thetruck frame before a defective dust boot can be replaced.

Accordingly, it is the purpose of this invention to provide a split orseam-type dust boot that lends itself to easy, rapid installation orreplacement, without removal of the tread brake assembly or partsthereof.

SUMMARY OF INVENTION According to the present invention, a novelsplit-type dust boot is provided wherein there is formed along themating edges at the seam of the boot a plurality of spaced longitudinalinterlocking ribs so arranged that when one edge is placed inoverlapping relation to the other, the two mating edges may be pressedinto an interlocking sealed relationship. If desired, interlocking ofthe ribbed mating edges may be effected by the aid of a slide elementmoved along these edges from an open to a closed position. When themating edges are sealingly interlocked passage of dirt, snow and waterto the interior of the boot is effectively prevented.

In the accompanying drawings:

FIG. 1 is a side elevational view of a brake assembly embodying theinvention, showing the exterior elements of the brake assembly in theirbrake applied position.

FIG. 2 is an isometric view showing the dust boot of the brake assemblyshown in FIG 1, the boot being illustrated in an open position.

FIG. 3 is an isometric view showing a second embodiment of the inventionwherein the dust boot embodies a slide fastener for effecting theopening and closing thereof, the boot being illustrated in an closedposition.

FIG. 4 is a cross-sectional view, taken along the line 4-4 of FIG. 3 andlooking in the direction of the arrows, showing the locked position ofthe two sets of interlocking fingers or ribs that constitute the seam ofthe boot.

FIG. 5 is a cross-sectional view similar to FIG. 4 but showing the twosets offingers or ribs in their unlocked position.

FIG. 6 is a cross-sectional view, taken along the line 6--6 of FIG. 3and looking in the direction of the arrows, showing certain details ofthe slide fastener not shown in FIG. 3.

As shown in FIG. 1 of the drawings, a pneumatic tread brake assembly,one of which is provided for each wheel of a railway passenger cartruck, is secured, as by several capscrews to a pair of angle bracketswhich are attached as by welding to the center sill of the passenger cartruck frame.

The brake assembly shown in FIG. 1 comprises a brakeshoe l for movementinto braking contact as shown with the tread of a wheel 2 of a cartruck, a brakehead 3 to which the brake shoe 1 is secured, as by a key4, an external brakehead hanger 5, and a sectionalized casing comprisinga main casing section 6 and a brake cylinder section 7.

Formed integral with the main casing section 6 is a pair of bosses 8provided with several spaced-apart threaded bores (not shown) forreceiving a like number of capscrews 9 whereby the main casing section 6is rigidly secured to a pair of angle brackets 10 attached as by weldingto a center sill (not shown) of a passenger car truck frame.

Slidably operable in a bore (not shown) in the casing section 7 is afluid actuated brake-applying piston (not shown) that is connectedthrough a suitable lever arrangement (not shown) to a brake rod (notshown) that at the end thereof exterior of the casing section 6 ispivotally connected to one of the brakehead hanger 5 and the brakehead3, as by a bolt 11 and a nut 12. The brakehead hanger 5 comprises twoidentical parallel links, only one of which is shown, disposedrespectively on the opposite sides of a bracket 13 integral with themain casing section 6, and suspended from the bracket 13, as by means ofa bolt 14.

In order to prevent the entrance of water, ice, and dirt to the interiorof the casing section 6, one end of a split or seam-type cone-shapedreplaceable dust boot 15, constituting a first embodiment of the presentinvention, surrounds an opening (not shown) in the main casing section 6through which the abovementioned brake rod extends.

As shown in FIG. 2 of the drawings, the cone-shaped dust boot 15 issplit along its conical surface, preferably along its slant height, asshown, from a flange 16 formed integral therewith at its smaller end toa flange 17 formed integral therewith at its larger end, it being seenfrom FIG. 2 that the split extends through these flanges. Accordingly,it is apparent that this split provides for the boot 15 being disposedin detachable surrounding relationship to the above-mentioned brake rodof a tread brake assembly so as to be readily removable and replaceablewithout disassembling the associated brake assembly or removing theassembly from the car truck.

The dust boot 15 is constructed of any suitable resilient material suchas, for example, rubber. Adjacent each edge of the longitudinal splitthere is provided a plurality of longitudinally extending spaced-apartfingers or ribs 18, the ribs along the lower side of the split beingformed on the exterior surface of the boot l5 and the ribs on the upperside being formed on the interior surface thereof. As can be seen fromFIG. 2 of the drawings, these ribs 18 extend from a point adjacent theright-hand side of the flange 16 along the exterior and interiorsurfaces of the boot 15 to the ends of a pair of short outwardlyextending tabs 19 and 20 which are formed integral with the flange I7and are disposed on the opposite sides of the split that extendstherethrough. These tabs 19 and 20 each comprise two integrally formedrectangular-shaped elements 21 and 22, the thickness of the elements 22being substantially twice the thickness of the elements 21 in order toprovide for the ribs 18 which extend along their respective oppositesides to the outer ends thereof, it being understood that the size andspacing of one set of ribs is the same as that of the other.

Assume that a tread brake assembly without a dust boot I5 has beensecured to the angle-brackets 10 by the capscrews 9, as shown in FIG. 1.Accordingly, subsequent to securing the brake assembly to the anglebrackets 10 and effecting a brake application, a split or seam-type boot15, as shown in FIG. 2, may have its adjacent edges gripped by the handsof a workman and then moved in opposite directions until the gap formedtherebetween is of sufficient width to enable the brake rod of the treadbrake assembly to pass therebetween. With the adjacent edges of the dustboot 15 held in this spread apart position by the workman, he can thenslip the boot over the brake rod. Thereafter, he will move the boot to aposition coaxial with the brake rod and then release his grip from theedges of the boot.

Next, the workman will move the upper tab 19 of the boot and the ribs 18thereon, which are coextensive with the ribs formed on the interiorsurface of the boot adjacent the upper edge of the seam or split, to aposition, as viewed in FIG. 5, in which this upper tab 19 is disposed infront of or so as to overlap the left-hand side of the lower tab 20. Itwill be understood that when the upper tab 19 is moved to this positionby the workman, the ribs 18 formed on the interior of the boot 15adterior of this boot adjacent the lower edge, as illustrated in FIG. 5.

Now, the workman will release the tab 19 and thereafter secure theflange 17 at the right-hand end of the boot 15 against the exteriorsurface of the main casing section 6 by means of the usual boot retainerring and capscrews which extend through smooth bores formed in thisretainer ring and have screw-threaded engagement with correspondingscrewthreaded bores provided in the casing section 6.

It will be noted that as these capscrews are tightened, the retainerring is rendered effective to push that portion of the two sets ofoverlapping ribs formed between the adjacent ends of the flange 17 intointerlocking relationship one with the other, or, in other words, fromthe unlocked position shown in FIG. to the interlocked position shown inFIG. 4 in which each set of ribs is disposed in the recesses between theribs of the other set, it being noted that the width of each rib at itsouter end is slightly greater than the width of the outer end of thecorresponding recess and the taper of one portion of each side of eachrib is different than the taper of the other portion of said sides. Asclearly shown in FIG. 5, the outer taper of the base portion of each rib18 is greater than the outer taper of the outer end portion of theseribs. Referring to FIG. 4, it will be seen that this structure of theribs 18, while in their interlocked position, provides a reasonablysmall area of contact between each adjacent pair of ribs which actualexperience has shown constitutes a better seal than is obtained whenthis area of contact is overly large. Accordingly, applicants structurepossesses a distinct advantage over heretofore used structures.

It will be remembered that the brake rod is now in its brakeappliedposition. Consequently, it will be understood that; (1) the bootoccupies its stretched position as shown in FIG. 2, (2) the flange 16surrounds the brake rod adjacent the bolt 11 (FIG. 1), (3) the bootretainer ring secures the flange 17 of the boot against the exteriorsurface of the casing section 6 and (4) the plurality of ribs 18 formedon the interior of the boot and extending between the flanges 16 and 17are disposed in front of the recesses between the ribs 18 formed on theexterior of the boot substantially as illustrated in FIG. 5. Since theboot now occupies a stretched position, the set of ribs on the interiorof the boot can be manually pressed into interlocking and sealingengagement with the set of ribs formed on the exterior of the boot asthe workman applies pressure by means of his forefinger and moves italong the split seam from either of the flanges 16 or 17 to the other.Likewise, the ribs 18 on the portion 22 of the tab 19 can be moved intointerlocking and sealing relationship with the corresponding ribs on theportion 22 of the tab 20 by the workman applying pressure by means ofhis forefinger to the portion 22 of tab 19 and moving this fingertherealong from the end thereof adjacent the flange 17 to the outer end.

Should the boot 15 become defective, so that it is necessary to replaceit with a new boot, it can be removed in the following manner:

Subsequent to effecting a brake application to position the boot 15 inits stretched position, the capscrews securing the boot retainer ring tothe casing section 6 are removed. Then, this retainer ring is moved fromthe position in which it abuts the flange 17 in the directionof the lefthand until it strikes the brake hanger 5 (FIG. 1). It can then bereleased so that it is supported by the conical portion of the bootadjacent the flange 16.

The seam formed by the two sets of interlocking ribs 18 can now beopened by the workman in the following manner:

He will grip the portion 21 of the tab 19 with his fingers andthereafter exert a pull thereon in the direction of the left hand, asviewed in FIG. 2, or, in other words, in a direction away from therectangulanshaped element 22 of the tab 20. This force exerted on thetab 19 is effective to pull the ribs 18 thereon out of interlockingengagement with the corresponding ribs on the tab 20, or, in other wordsmove these ribs from the interlocked position shown in FIG. 4 to theunlocked position shown in FIG. 5.

Subsequent to thus unlocking the tabs 19 and 20, the remainder of thesplit seam may be unlocked or open by the workman exerting a pressure bymeans of his finger between or against the two overlapping portions ofthe seam and moving this finger therealong toward and to the flange 16thus causing withdrawal of one set of ribs from interlocking en gagementwith the other set thereby opening the seam.

Subsequent to thus opening the seam, the adjacent edges can be manuallyspread apart and the boot 15 then removed from surrounding relationshipwith the brake rod.

A new boot may now be installed in the manner hereinbefore explained.

According to a second embodiment of the invention shown in FIG. 3, adust boot identical to the boot 15 of the first embodiment is providedwith a slide-fastener element 23 which is employed to effectuate theinterlocking and unlocking of the ribs on the mating edges of the boot.Accordingly, like reference numerals have been used to designate thestructure shown in FIG. 3 which is identical with that shown in FIG. 2and already described. Only such features of the structure shown in FIG.3 which is identical with that shown in FIG. 2 and already described.Only such features of the structure of the embodiment of FIG. 3 whichdiffer from that of the embodiment shown in FIG. 2 will be hereinafterdescribed.

According to the embodiment of the invention shown in FIG. 3, the oneset of the ribs 18 is moved, into or out of interlocking and sealingengagement with the other set accordingly as the slide-fastener element23 is moved in one direction or the other along the split seam.

The structural details of the slide-fastener element 23 are shown inFIGS. 3 and 6 of the drawings, one end of this slidefastener element 23appearing in FIG. 3. This end of element 23 resembles somewhat theletter S and comprises three parallel spaced-apart metallic strips 24,25, and 26, the center strip 25 being disposed from each of the twoouter strips a distance substantially equal to the thickness of therectangular-shaped element 22 of the tabs 19 and 20 which elements aredisposed therebetween. At the right-hand-end of the slide-fastenerelement 23, as shown in FIG. 3, the top edge of the center strip 25 isintegrally connected by a short strip to the adjacent top edge of theright-hand outer strip 26. Likewise, the .bottom edge of the centerstrip 25 is integrally connected by a second short strip to the adjacentbottom edge of the lcft-hand outer strip 24, it being noted that thesetwo short strips are parallel and form a right angle with each of thetwo strips which are respectively connected thereby. It will be furthernoted from FIG. 3 that the free ends of the two outer strips 24 and 26are bent through an angle of and that these bent ends are disposed awayfrom the center strip 25 a distance substantially equal to the thicknessof the rectangular-shaped elements 21 of the tabs 19 and 20 whichelements are disposed therebetween. From the foregoing, it is apparentthat while the slide-fastener element 23 occupies the position shown inFiG. 3 the end thereof shown provides two parallel tracks for theexterior ends of the tabs 19 and 20.

As can be seen from FIG. 6 of the drawings, the length of the centermetallic strip 25 is less than that of the two outside strips 24 and 26.Furthermore, as viewed in FIG. 6, the upper end of the center strip 25is tapered to form a wedge which, as shown, is disposed between theelement 22 of the tab 19 and the element 22 of the tab 20.

As shown in FIGS. 3 and 6, formed integral with the strip 24 andextending outward therefrom is a web 27 having therein an elongated slot28 into which extends the ends of two parallel spaced-apart fingersformed at one end of a handle 29 it being understood that the ends ofthese fingers are bent so as to form a right angle and extend into theslot 28 from the respective opposite sides of the web 27. The handle 29serves as a means by which the slide-fastener element 23 can be moved inone direction or in an opposite direction to open or close the seam inthe boot 15 in a manner now to be described.

Assuming that the seam in the boot shown in FIG. 3 is closed and thatthe slide-fastener element 23 occupies the position shown, the scam inthe boot may be opened by a workman grasping the handle 29 between hisforefinger and thumb and then exerting a pull on this handle in thedirection to transmit a force to the slide-fastener element 23 via theweb 27 so as to act on element 23 in the direction of the left hand, asviewed in FIG. 3, or in an upward direction as viewed in FIG. 6. It willbe understood that the magnitude of this force is sufficient to effectmovement of the slide-fastener element 23 relative to the tabs 19 and20.

Referring to FIG. 6, it can be seen that as the slide-fastener element23 is moved in an upward direction, the center metallic strip 25, whichis disposed between the element 22 of the tab 19 and the element 22 ofthe tab 20, is effective to pull the ribs 18 on the element 22 of thetab out of the corresponding recesses or indentations between the ribs18 on the element 22 of the tab 20 or, in other words, to move theelement 22 and ribs 18 of the tab 20 relative to the element 22 and ribs18 of the tab 19 from the interlocked and sealed position shown in FIG.4 to the unlocked and unsealed position shown in FIG. 5.

From the foregoing it is apparent that the seam in the boot 15 shown inFIG. 3 can be opened by the workman moving the slide-fastener element 23from the position in which it is shown in the direction of the left handor toward the flange 16 until this slide-fastener element 23 is movedpast the left-hand end of the outside element 22 shown in FIG. 3 andlikewise past the left-hand end of the inside element 22 which does notappear in FIG. 3. With the slide-fastener element 23 in this left-handposition, the workman can remove the slide-fastener element 23 from thesplit boot 15.

It will be understood from the foregoing that the inside ribs 18 alongthe upper side of the longitudinal split are now withdrawn from therecesses between the outside ribs 18 along the lower side of thislongitudinal split. Accordingly, the two longitudinal edges of the splitseam are now separated. Assuming that a brake application has beeneffected, the dust boot 15 can now be placed in coaxial surroundingrelation to the brake rod in the same manner as hereinbefore described.

With the upper tab 19 of the boot 15 disposed in front of or overlappingthe lower tab 20, the workman will place the slide-fastener element 23between the right-hand side of the flange l6 and the left-hand end ofthe inside and outside elements 22. Then, with these elements 22 spreadapart a distance equal to the thickness of the strip 25, he will exert apull on the handle 29 of the slide-fastener element 23 so as to move itin the direction of the right hand as viewed in FIG. 3, so that thelower end of the center strip 25, as viewed in FIG. 6, passes betweenthe two elements 22.

Since the strips 25 and 26 of the slide-fastener element 23 are tapered,as shown in FIG. 6, it will be understood that if the slide-fastenerelement 23 is now moved by the handle 29 downward, as viewed in the FIG.6, or in the direction of the right hand, as viewed in FIG. 3 until thiselement 23 reaches the position shown in FIG. 3, the ribs 18 of the tab20 will be forced into the corresponding recesses between the ribs 18 ofthe tab 19, or, in other words, from the position shown in FIG. 5 to theposition shown in FIG. 4 in which one set of ribs 18 are in interlockingand sealing engagement with the other set.

The flange 17 at the right-hand end of the boot 15 can now be securedagainst the exterior surface of the main casing section 6 of the treadbrake assembly by means of the usual boot retainer ring and capscrews inthe manner hereinbefore described for the first embodiment of theinvention.

direction of the left hand until it reaches the position in which it canbe removed from the boot in the manner hereinbefore explained. Thedefective boot can then be removed from coaxial surrounding relation tothe brake rod and a new boot installed in its place in the mannerhereinbefore explained.

In order to provide a more perfect seal between the two sets ofinterlocking ribs 18 forming the seam in the boot 15, subsequent toclosing the seam by moving the slide-fastener elc ment 23 to theposition shown. in FIG. 3, a cement or bonding agent, such as, forexample, room temperature vulcanization silicone rubber may be appliedalong the length of the seam at the location denoted by the numeral 30in FIG. 4 of the drawings.

Subsequent to the hardening of this cement or bonding agent, the seamcannot be opened by means of the slidefastener element 23. Accordingly,upon the boot becoming defective, in order to remove the boot fromsurrounding relation to the brake rod, a longitudinal seam would have tobe cut from one end of the boot to the other by suitable means, such as,for example, a sharp knife, it being understood that this cut or slitextends through the flanges 16 and 17.

Having thus described the invention, what we claim as new and desire tosecure by Letters Patent, is:

l. A hollow truncated cone-shaped resilient boot having two opposingends and a radially outwardly extending flange at each of said ends,wherein the improvement comprises:

a. the development of said hollow truncated cone-shaped boot constitutesa sheet of material perimetrically defined by said two opposing ends anda pair of opposing edges each having a tab disposed as an extension ofthe respective edge and extending through said flange on one of saidends, and

b. releasable locking spaced-apart ribs on each of said opposing edgesterminating atone end at the exterior end of the corresponding tab andat the opposite end adjacent the flange at the other of said pair ofends, said ribs on each of said opposing edges movable into releasableinterlocking engagement with said ribs on the other opposing edge toform said hollow truncated cone-shaped boot and comprise a seamextending from one of said opposing ends to the other and through saidflanges.

2. A hollow truncated cone-shaped flexible boot, as recited in claim 12,further characterized in that one-half the width of said tabs issubstantially twice the thickness of the other half, and said one-halfof said tab width includes parallel grooves forming therebetween saidplurality of ribs.

3. A hollow truncated cone-shaped flexible boot, as recited in claim 2,further characterized by a slide-fastener element movable in onedirection to effect interlocking engagement of the ribs on one of saidedges with the ribs on the other edge and movable in the oppositedirection to effect disengagement of said ribs on said respective edges.

4. A hollow truncated cone-shaped flexible boot, as recited in claim 2,further characterized in that the height of said ribs is substantiallyequal to the thickness of said other half of said tabs.

(2 3 3? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,638,503 Dated February 1, 1972 Inventor(s) Jose h-G. Stipanovic andEarl E. Allan It is certified that error appearsvin the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 6, line 52, numeral "12" should be --l-- '1 Signed and sealedthis 25th day of July 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,J'R. 7 ROBERT GO'ITSCHALK Attesting OfficerCommissioner of Patents

1. A hollow truncated cone-shaped resilient boot having two opposingends and a radially outwardly extending flange at each of said ends,wherein the improvement comprises: A. the development of said hollowtruncated cone-shaped boot constitutes a sheet of materialperimetrically defined by said two opposing ends and a pair of opposingedges each having a tab disposed as an extension of the respective edgeand extending through said flange on one of said ends, and b. releasablelocking spaced-apart ribs on each of said opposing edges terminating atone end at the exterior end of the corresponding tab and at the oppositeend adjacent the flange at the other of said pair of ends, said ribs oneach of said opposing edges movable into releasable interlockingengagement with said ribs on the other opposing edge to form said hollowtruncated cone-shaped boot and comprise a seam extending from one ofsaid opposing ends to the other and through said flanges.
 2. A hollowtruncated cone-shaped flexible boot, as recited in claim 12, furthercharacterized in that one-half the width of said tabs is substantiallytwice the thickness of the other half, and said one-half of said tabwidth includes parallel grooves forming therebetween said plurality ofribs.
 3. A hollow truncated cone-shaped flexible boot, as recited inclaim 2, further characterized by a slide-fastener element movable inone direction to effect interlocking engagement of the ribs on one ofsaid edges with the ribs on the other edge and movable in the oppositedirection to effect disengagement of said ribs on said respective edges.4. A hollow truncated cone-shaped flexible boot, as recited in claim 2,further characterized in that the height of said ribs is substantiallyequal to the thickness of said other half of said tabs.